roger rosa

Definitely, I don't think it is an issue of AP itself, it has to do with AP file format Reader/writer for targa or Tiff. Since other application support preserving the alpha and RGB channels separately. I am no programmer but I would not think that this is such a major work to rectify, a save as Packed / or preserver Alpha tick on export ?

I would ask also, Can you add a 4 th grayscale channel to pack in the alpha channel of that image and save it out ? So far this does not work as packing since Affinity just pre multiplies (is that the word) the RGB with the alpha instead of keeping each channel separate.

I have to agree with opermarks and others that are voicing their request for a proper Alpha Channel packing support. Right now it becomes impossible to have Affinity as part of a pipeline where you need the alpha channel to store additional information. If I make a texture with packing a grayscale map on the alpha of a texture, it opens in Photo with a completely White alpha. If you try and pack yourself information in an Alpha channel in Photo and Export it , it will clip all information in RGB with the opacity values of the alpha without giving you any control over whether you want pre/unpremultiplied. Unreal engine supports it, Substance Painter / Designer supports it. And aside from photographers the other markets would clearly see the benefit of Photo supporting Alpha channel Packing. Right now , I basically avoid Affinity for any work on Images / textures. It is quite disappointing.